Miniature single actuator scanner for angle multiplexing with circularizing and pitch correction capability

ABSTRACT

The present invention provides a scanner comprising: a reflector component; means supporting the reflector component for pivoting with respect to the MCR to provide a scan which is stationary with respect to the OCR; means for enabling the support means to provide controlled pivoting of the reflector component; a magnet component which causes pivoting of the reflector component when actuated; and means for actuating the magnet component to thereby cause pivoting of the reflector component. Also provided is a scanner comprising a reflective prism for providing a circularized scanning beam, a prism carrier and magnet suspension assembly, and flexure means connected to the assembly to enable the prism to controllably pivot: (1) with respect to the MCR axis to provide a scan which is stationary with respect to the OCR; and (2) with respect to a pitch axis orthogonal to the MCR to provide an orthogonal scan.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application makes reference to and claims the priority date of thefollowing co-pending U.S. Provisional Patent Application: U.S.Provisional App. No. 60/835,108, entitled “Miniature Single ActuatorScanner for Angle Multiplexing with Circularizing and OrthogonalScanning Capability” filed Aug. 3, 2006. The entire disclosure andcontents of the above applications are hereby incorporated by reference.

STATEMENT OF JOINT RESEARCH AGREEMENT

In compliance with 37 C.F.R. §1.71(g) (1), disclosure is herein madethat the claimed invention was made pursuant to a Joint ResearchAgreement as defined in 35 U.S.C. 103 (c) (3), that was in effect on orbefore the date the claimed invention was made, and as a result ofactivities undertaken within the scope of the Joint Research Agreement,by or on the behalf of Nintendo Co., Ltd. and InPhase Technologies, Inc.

BACKGROUND

1. Field of the Invention

The present invention broadly relates to a device comprising a scannerwhich may be used in, for example, angle multiplexing of holographicdata to carry out a stationary optical center of rotation (OCR) scan.The present invention also broadly relates to a device comprising ascanner which may use a single reflective prism for circularizing ascanning beam, for carrying out a stationary OCR scan and/or forcarrying out an orthogonal scan for pitch control. The present inventionfurther broadly relates to a device comprising a flexure assembly and areflective component suspension assembly for use in such scanners.

2. Related Art

Developers of information storage devices and methods continue to seekincreased storage capacity. As part of this development, holographicmemory systems have been suggested as alternatives to conventionalmemory devices. Holographic memory systems may be designed to recorddata as one bit of information (i.e., bit-wise data storage). See McLeodet al. “Micro-Holographic Multi-Layer Optical Disk Data Storage,”International Symposium on Optical Memory and Optical Data Storage (July2005). Holographic memory systems may also be designed to record anarray of data that may be a 1-dimensional linear array (i.e., a 1×Narray, where N is the number linear data bits), or a 2-dimensional arraycommonly referred to as a “page-wise” memory system. Page-wise memorysystems may involve the storage and readout of an entire two-dimensionalrepresentation, e.g., a page of data. Typically, recording light passesthrough a two-dimensional array of low and high transparency areasrepresenting data, and the system stores, in three dimensions, the pagesof data holographically as patterns of varying refractive indeximprinted into a storage medium. See Psaltis et al., “HolographicMemories,” Scientific American, November 1995, where holographic systemsare discussed generally, including page-wise memory systems.

Holographic data storage systems may perform a data write (also referredto as a data record or data store operation, simply “write” operationherein) by combining two coherent light beams, such as laser beams, at aparticular point within the storage medium. Specifically, a data-encodedlight beam may be combined with a reference light beam to create aninterference pattern in the holographic storage medium. The patterncreated by the interference of the data beam and the reference beamforms a hologram which may then be recorded in the holographic medium.If the data-bearing beam is encoded by passing the data beam through,for example, a spatial light modulator (SLM), the hologram(s) may berecorded in the holographic medium.

Holographically-stored data may then be retrieved from the holographicdata storage system by performing a read (or reconstruction) of thestored data. The read operation may be performed by projecting areconstruction or probe beam into the storage medium at the same angle,wavelength, phase, position, etc., as the reference beam used to recordthe data, or compensated equivalents thereof. The hologram and thereference beam interact to reconstruct the data beam.

A technique for increasing data storage capacity is by multiplexingholograms. Multiplexing holograms involves storing multiple holograms inthe holographic storage medium, often in the same volume or nearly thesame volume of the medium. Multiplexing may carried out by varying anangle, wavelength, phase code, etc., in recording and then later readingout the recorded holograms. Many of these methods rely on a holographicphenomenon known as the Bragg effect to separate the holograms eventhough they are physically located within the same volume of media.Other multiplexing methods such as shift and, to some extentcorrelation, use the Bragg effect and relative motion of the media andinput laser beams to overlap multiple holograms in the same volume ofthe media.

In angle multiplexing, multiple holograms may be stored in the samevolume of the holographic storage medium by varying the angle of thereference beam during recording. For example, data pages may be recordedin the holographic storage medium at many angles, exhausting the dynamicrange or “address space” of a given volume of the medium. Each locationin the “address space” (or each data page) corresponds to the angle of areference beam. During recording, the reference beam scans through manydiscrete angles as data pages are written. Conversely, during readout, aconjugate reference beam (sometimes referred to as a “probe beam”) mayprobe each data page at its corresponding angle. In other words, thescanner may be used for either recording or readout of the data pages.

SUMMARY

According to a first broad aspect of the present invention, there isprovided a device comprising a scanner having a mechanical center ofrotation and an optical center of rotation, the scanner comprising:

-   -   a reflector component for reflecting an input scanning beam to        provide an output scanning beam;    -   means supporting the reflector component for pivoting about one        end of the reflector component with respect to the mechanical        center of rotation so that the output scanning beam provides a        scan which is stationary with respect to the optical center of        rotation;    -   means for enabling the support means to provide controlled        pivoting of the reflector component about the one end;    -   a magnet component which when actuated causes pivoting of the        reflector component about the one end; and    -   means for actuating the magnet component to thereby cause        pivoting of the reflector component about the one end.

According to a second broad aspect of the invention, there is provided adevice comprising a scanner having a mechanical center of rotation axis,an optical center of rotation, and a pitch axis orthogonal to themechanical center of rotation axis, the scanner comprising:

-   -   a reflective prism for circularizing an elliptical input        scanning beam to provide a circularized output scanning beam;    -   a prism carrier and magnet suspension assembly from which the        reflective prism is mounted;    -   flexure means connected to the carrier and suspension assembly        for enabling the reflective prism to controllably pivot:        -   at one end of the reflective prism with respect to the            mechanical center of rotation axis so to that the output            scanning beam provides a scan which is stationary with            respect to the optical center of rotation; and        -   with respect to the pitch axis so that the output scanning            beam provides an orthogonal scan;    -   a magnet component which, when actuated, causes the reflective        prism to controllably pivot with respect to one or more of the        mechanical center of rotation axis and the pitch axis; and    -   means for actuating the magnet component to thereby cause the        reflective prism to controllably pivot with respect to one or        more of the mechanical center of rotation axis and the pitch        axis.

According to a third broad aspect of the invention, there is provided adevice comprising a flexure assembly and a reflective componentsuspension assembly connected to the flexure assembly, the flexureassembly comprising:

-   -   a pair of spaced apart upper flexure components which enable the        suspension assembly to controllably pivot with respect to a        stationary mechanical center of rotation axis;    -   each of the upper flexure components having a lower base        segment, an upper segment, and at least one flexure segment        diagonally connecting the lower base segment of the upper        flexure component to the upper segment of the upper flexure        component; and    -   a pair of spaced apart lower flexure components which enable the        suspension assembly to controllably pivot with respect to an        axis orthogonal to the mechanical center rotation axis;    -   one of the lower flexure components being mounted underneath one        of the upper flexure components, the other of the lower flexure        components being mounted underneath the other of the upper        flexure components;    -   each of the lower flexure components having a lower base        segment, an upper segment, and at least one flexure segment        extending diagonally and outwardly with respect to the        orthogonal axis, and connecting the lower base segment of the        lower flexure component to the upper segment of the lower        flexure component.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be described in conjunction with the accompanyingdrawings, in which:

FIG. 1 represents schematically an illustrative readout scanning carriedout using a conventional galvo scanner (as the readout scanner) of datarecorded in a holographic storage medium by angle multiplexing;

FIG. 2 schematically illustrates a single actuator scanner system thatmay perform identically to the conventional two-axis galvo scannerillustrated in FIG. 1;

FIG. 3 schematically illustrates a readout scanning about a stationaryoptical center of rotation (OCR) using a single mirror with twoactuators, one being a linear actuator, the other being a rotaryactuator;

FIG. 4 represents a perspective view of an embodiment of a stationaryOCR scanner according to the present invention;

FIG. 5 is an exploded view of the embodiment of the scanner of FIG. 4;

FIG. 6 represents a perspective view of an another embodiment of anintegrated single-axis stationary OCR scanner according to the presentinvention using a single anamorphic reflective prism;

FIG. 7 is a sectional view of the scanner of FIG. 6 taken along line7-7;

FIG. 8 is a top plan view of the scanner of FIG. 6;

FIG. 9 is perspective view of the combination of the forward section ofthe prism carrier and magnet assembly and the flexure assembly used inthe scanner of FIG. 6;

FIG. 10 is a sectional view of the suspension assembly and flexureassembly of FIG. 9 taken along line 10-10;

FIG. 11 is scanning diagram illustrating schematically the passage ofthe input beam through the prism of FIG. 6 when positioned at one angle;

FIG. 12 is a scanning diagram illustrating schematically the passage ofthe input beam through the prism of FIG. 6 when rotated or pivoted tothree different angles; and

FIG. 13 is a circularization diagram illustrating the circularizationoccurring during the scans shown in FIG. 12.

DETAILED DESCRIPTION

It is advantageous to define several terms before describing theinvention. It should be appreciated that the following definitions areused throughout this application.

DEFINITIONS

Where the definition of terms departs from the commonly used meaning ofthe term, applicant intends to utilize the definitions provided below,unless specifically indicated.

For the purposes of the present invention, directional terms such as“top”, “bottom”, “above”, “below”, “left”, “right”, “horizontal”,“vertical”, “up”, “down”, etc. are merely used for convenience indescribing the various embodiments of the present invention. Theembodiments of the present invention may be oriented in various ways.For example, the embodiments shown in FIGS. 1 through 13 may be flippedover, rotated by 90° in any direction, etc.

For the purposes of the present invention, the term “laser” refers toconventional lasers, as well as laser diodes (LDs).

For the purposes of the present invention, the term “light source”refers to any source of electromagnetic radiation of any wavelength, forexample, from a laser, etc. Suitable light sources for use inembodiments of the present invention include, but are not limited to,those obtained by conventional laser sources, e.g. the blue and greenlines of Ar⁺ (458, 488, 514 nm) and He—Cd lasers (442 nm), the greenline of frequency doubled YAG lasers (532 nm), and the red lines ofHe—Ne (633 nm), Kr⁺ lasers (647 and 676 nm), and various laser diodes(LDs) (e.g., emitting light having wavelengths of from 290 to 900 nm).

For the purposes of the present invention, the term “spatial lightintensity” refers to a light intensity distribution or pattern ofvarying light intensity within a given volume of space.

For the purposes of the present invention, the terms “holographicgrating,” “holograph” or “hologram” (collectively and interchangeablyreferred to hereafter as “hologram”) are used in the conventional senseof referring to an interference pattern formed when a signal beam and areference beam interfere with each other. In cases wherein digital datais recorded, the signal beam may be encoded with a data modulator, e.g.,a spatial light modulator, etc.

For the purposes of the present invention, the term “holographicrecording” refers to the act of recording a hologram in a holographicstorage medium. The holographic recording may provide bit-wise storage(i.e., recording of one bit of data), may provide storage of a1-dimensional linear array of data (i.e., a 1×N array, where N is thenumber linear data bits), or may provide 2-dimensional storage of a pageof data.

For the purposes of the present invention, the term “multiplexingholograms” refers to recording, storing, etc., a plurality of hologramsin the same volume or nearly the same volume of the holographic storagemedium by varying a recording parameter(s) including, but not limitedto, angle, wavelength, phase code, shift, correlation, peristrophic,etc. For example, angle multiplexing involves varying the angle of thereference beam during recording to store a plurality of holograms in thesame volume. The multiplexed holograms that are recorded, stored, etc.,may be read, retrieved, reconstructed, etc., by using the same recordingparameter(s) used to record, store, etc., the respective holograms.

For the purposes of the present invention, the term “holographic storagemedium” refers to a component, material, etc., that is capable ofrecording and storing, in three dimensions (i.e., the X, Y and Zdimensions), one or more holograms as one or more pages as patterns ofvarying refractive index imprinted into the medium. Examples ofholographic media useful herein include, but are not limited to, thosedescribed in: U.S. Pat. No. 6,103,454 (Dhar et al.), issued Aug. 15,2000; U.S. Pat. No. 6,482,551 (Dhar et al.), issued Nov. 19, 2002; U.S.Pat. No. 6,650,447 (Curtis et al.), issued Nov. 18, 2003, U.S. Pat. No.6,743,552 (Setthachayanon et al.), issued Jun. 1, 2004; U.S. Pat. No.6,765,061 (Dhar et al.), Jul. 20, 2004; U.S. Pat. No. 6,780,546(Trentler et al.), issued Aug. 24, 2004; U.S. patent application Ser.No. 2003-0206320 (Cole et al.), published Nov. 6, 2003, and U.S. patentapplication Ser. No. 2004-0027625 (Trentler et al.), published Feb. 12,2004, the entire contents and disclosures of which are hereinincorporated by reference.

For the purposes of the present invention, the term “data page” or“page” refers to the conventional meaning of data page as used withrespect to holography. For example, a data page may be a page of data(i.e., a two-dimensional assembly of data), one or more pictures, etc.,to be recorded in a holographic storage medium.

For the purposes of the present invention, the term “recording light”refers to a light source used to record into a holographic storagemedium. The spatial light intensity pattern of the recording light iswhat is recorded.

For the purposes of the present invention, the term “recording data”refers to storing or writing holographic data in a holographic storagemedium.

For the purposes of the present invention, the term “reading data”refers to retrieving, recovering, or reconstructing holographic datastored in a holographic storage medium.

For the purposes of the present invention, the term “X-Y plane”typically refers to the plane defined by holographic medium thatencompasses the X and Y linear directions or dimensions. The X and Ylinear directions or dimensions are typically referred to herein,respectively, as the dimensions known as length (i.e., the X-dimension)and width (i.e., the Y-dimension).

For the purposes of the present invention, the terms “Z-direction” and“Z-dimension” refer interchangeably to the linear dimension or directionperpendicular to the X-Y plane, and is typically referred to herein asthe linear dimension known as thickness.

For the purposes of the present invention, the term “data modulator”refers to any device that is capable of optically representing data inone or two-dimensions from a signal beam.

For the purposes of the present invention, the term “spatial lightmodulator” (SLM) refers to a data modulator device that is anelectronically controlled, active optical element.

For the purposes of the present invention, the term “refractive indexprofile” refers to a three-dimensional (X, Y, Z) mapping of therefractive index pattern recorded in a holographic storage medium.

For the purposes of the present invention, the term “data beam” refersto a recording beam containing a data signal. As used herein, the term“data modulated beam” refers to a data beam that has been modulated by amodulator such as a spatial light modulator (SLM).

For the purposes of the present invention, the terms “dynamic range” or“M#” relate to an intrinsic property of a holographic medium and areused in the conventional sense to refer to the total response of thatmedium when portioned among the one or more holograms recorded in acommon volume and related to the index change and thickness of thatmedium. See Shelby, “Media Requirements for Digital Holographic DataStorage,” Holographic Data Storage, Section 1.3 (Coufal, Psaltis,Sincerbox Eds. 2003).

For the purposes of the present invention, the term “transmission”refers to transmission of a light beam from one component, element,article, etc., to another component, element, article, etc.

For the purposes of the present invention, the term “scanner” refers toa steering device for a light beam used to read, analyze, etc., imagesrecorded in a holographic storage medium.

For the purposes of the present invention, the term “OCR” refers to orrepresents the optical center of rotation. In some embodiments, the OCRmay correspond to the center of the scan rotation, the center of thehologram volume, or both the center of the scan rotation and the centerof the hologram volume.

For the purposes of the present invention, the term “stationary OCR”refers to where all scan angles have a common intersection point in ahologram or holographic storage medium. For example, a stationary OCRscan may refer to a scan motion or movement where all scan anglesintersect at a common point.

For the purposes of the present invention, the term “MCR” refers to orrepresents the mechanical center of rotation. The MCR may define oneaxis about which one corner or end of a reflector component (e.g., aprism) may rotate or pivot, even though the one corner or end of thereflector component is not necessarily coincident with or the same asthe MCR. For example, the one corner or end of the reflector componentmay be coincident with or close to the MCR, but may also be located orpositioned at some location which is further away from the MCR. In someembodiments, the MCR may define a single axis which the one corner orend of the reflector component is required to rotate or pivot about orwith respect to so as to provide a stationary OCR.

For the purposes of the present invention, the term “PA” refers to orrepresents the pitch axis. The PA is a mechanical axis of rotation orpivoting which is orthogonal to the axis of the MCR, but which placesthe OCR near the center of the holographic medium. For example, FIG. 2shows a PA indicated as 248.

For the purposes of the present invention, the term “orthogonalscanning” refers to a scan carried out by rotation or pivoting of thereflective component (e.g., prism) of the scanner about the PA. In someembodiments, orthogonal scanning about the PA may be used to carry outan orthogonal scan. Orthogonal scans may be performed in conjunctionwith scans (e.g., stationary OCR scans) carried out by rotating orpivoting of the reflector component relative to the MCR axis. Theseorthogonal scans may be very small in magnitude (e.g., the reflectorcomponent may be rotated or pivoted about the PA only up to about 0.5°in either direction) and are often used to provide pitch control tocompensate for small errors in the tilt or positioning of the hologramor holographic storage medium.

For the purposes of the present invention, the term “anamorphic prism”refers to a prism design used in beam shaping that causes intentionaldistortion of a beam image. For example, an anamorphic prism may be usedto change the shape of an elliptical light beam by, in effect,“stretching” the beam along the shorter dimension to provide a morecircular-shaped beam.

For the purposes of the present invention, the term “Littrow prism”refers to a type of anamorphic prism.

For the purposes of the present invention, the term “circularization”refers to a beam conditioning process wherein an elliptical beam (e.g.,an elliptical-shaped output beam from a laser diode) may be made into,converted to, etc., a circular-shaped beam.

For the purposes of the present invention, the term “in phase sinusoids”refers to sinusoidal voltage or current traces (for example, as seen onan oscilloscope) which have coincident peaks and valleys.

For the purposes of the present invention, the term “degrees of freedom”refers to the number of constraints required to describe a motion ormovement mechanically, optically, or mathematically.

For the purposes of the present invention, the term “two degrees offreedom” refers to systems, devices, etc., having two constraints.

For the purposes of the present invention, the term “translate” refersto lateral or linear motion or movement along a linear longitudinalaxis.

For the purposes of the present invention, the term “rotary galvoactuator” refers to galvanometer, e.g., a mirror which is rotated,pivoted, etc., by a motor, such as, for example, an electric motor.

For the purposes of the present invention, the term “master galvo”refers to a galvo assigned to an independent variable of a two degree offreedom constraint equation.

For the purposes of the present invention, the term “slave galvo” refersto a galvo assigned to a dependent variable of a two degree of freedomconstraint equation.

For the purposes of the present invention, the term “control rule”refers to a two degree of freedom constraint equation.

For the purposes of the present invention, the terms “motion” or“movement” refer interchangeably to any form of motion or movement, forexample, linear movement, rotational movement, pivotal movement, etc.

For the purposes of the present invention, the term “actuator” refers toa device that causes a magnet component to impart motion, movement, etc.Suitable actuators may include, solenoids (e.g. voice coils), steppermotors, etc.

For the purposes of the present invention, the term “voice coil” refersto a solenoid-type actuator.

For the purposes of the present invention, the term “Cardan suspension”refers to a joint, linkage, connection, etc., between two othercomponents, for example, two rigid rods, which allows or enables thecomponents (e.g., rigid rods) which are joined, linked, connected, etc.,to bend, pivot, in any direction, relative to the joint, linkage,connection, etc. A Cardan suspension may also be referred to as a“universal joint,” U-joint, Cardan joint, Hardy-Spicer joint, Hooks'sjoint, etc. One example of a Cardan suspension may comprise a pair ofhinges joined, linked, connected to each other, or located closetogether, but where the hinges are joined, linked, connected, oriented,etc., such that the respective pivot, rotational, etc., axes of thehinges are orthogonal (perpendicular) to each other.

For the purposes of the present invention, the term “gimbal” refers to amechanical device, means, mechanism, suspension, etc., that allows orenables the pivoting, rotation, etc., of an object in multipledimensions. A gimbal may be made up of two or three pairs of pivotsmounted, connected, linked, joined, etc., on axes at right angles (i.e.,orthogonally or perpendicularly). For example, a three-axis gimbal mayallow or enable a mounted object to remain in a horizontal planeregardless of the motion of its support. An example of a two-axis gimbalis a Cardan suspension.

For the purposes of the present invention, the term “area sensor” refersto a sensor having a plurality of light-sensitive receptor sites, e.g.“pixels”, arranged in a two-dimensional array and may be useful fordetecting, capturing, etc., holograms recovered from a holographicstorage medium. Area sensors often provide an electrical output signalthat represents a two-dimensional image of the illumination falling onits light-sensitive surface, e.g. convert captured images to digitaldata for processing by system electronics. Area sensors may be referredto interchangeably herein as “cameras” and may include complementarymetal-oxide-semiconductor (CMOS) sensors, charge-coupled CCD sensorscomponents, etc.

DESCRIPTION

FIG. 1 represents an illustrative readout scanning carried out using aconventional galvo scanner (as the readout scanner), indicated generallyas 100, of data recorded in the holographic storage medium by anglemultiplexing. Readout scanner 100 is shown with a holographic storagemedium 104 which has an upper surface 106, a reflective backing 108 tofacilitate miniaturization, and a midpoint 110. The incoming readoutreference beam 112 is represented by three beam lines corresponding tothe top of the beam (beam line 112-1), middle of the beam (beam line112-2), and the bottom of the beam (beam line 112-3). Scan 116 (see beamlines 116-1, 116-2 and 116-3) represents the start angle, scan 120 (seebeam lines 120-1, 120-2 and 120-3) the middle angle, and scan 124 (seebeam lines 124-1, 124-2 and 124-3) the end angle of the dynamic range.The optical center of rotation (“OCR”) is indicated by arrow 132. Alsoshown in FIG. 1 is a first mirror 140 which may be adjusted or pivotedto different angles (e.g. represented by positions 140-1, 140-2 and140-3), and a second mirror 148 which may also be adjusted or pivoted todifferent angles (e.g., represented by positions 148-1, 148-2 and148-3). Beam lines 116-1, 116-2 and 116-3 represent the respectivereflections of top 112- 1, middle 112-2 and bottom 112-3 of beam 112when the first and second mirrors 140 and 148 are at positions 140-3 and148-3. Similarly beam lines 120-1, 120-2 and 120-3 represent therespective reflections of top 112-1, middle 112-2 and bottom 112-3 ofbeam 112 when the first and second mirrors 140 and 148 are at positions140-2 and 148-2, while beam lines 124-1, 124-2 and 124-3 represent therespective reflections of top 112-1, middle 112-2 and bottom 112-3 ofbeam 112 when the first and second mirrors 140 and 148 are at positions140-1 and 148-1. As further shown in FIG. 1, OCR 132 represents, at theintersection of midpoint 110 and beam lines 116-2, 120-2 and 124-2, boththe center of the reference beam rotation, as well as the center of thehologram volume, by readout scanner 100.

Recording scanners that have a stationary OCR at the hologram centroidminimize the size of each non-overlapping recording location and thusmake best use of the dynamic range of the holographic storage medium.During readout such scanners may minimize cross-talk from holograms atdifferent addresses. Scanners with a stationary OCR also minimize therequired size of the reference beam and thus minimize power required fora given energy density. In order to keep the OCR stationary during thescan of data recorded in a holographic storage medium by anglemultiplexing, the probe (scanning) beam used in the scanning should havetwo degrees of freedom, e.g., should be able to rotate or pivot, as wellas translate. Such rotation/pivoting and translation of the scanningbeam requires two degrees of freedom, for example, such as may beprovided by two rotary galvo actuators. But these two degrees of freedomare not independent in these two rotary galvo actuators, in that theangle of the “slave galvo” may be constrained to the angle of the“master galvo” through the use of a control rule that is sufficient tokeep the OCR stationary.

FIG. 2 illustrates a scanning system, indicated generally as 200, usinga single actuator scanner that may perform identically to theconventional two-axis galvo scanner of FIG. 1. The single actuatorscanner system 200 is shown in FIG. 2 with a holographic storage medium204 which has an upper surface 206, a reflective backing 208 tofacilitate miniaturization, and a midpoint 210. The incoming inputreadout beam 212 is represented by three beam lines corresponding to thetop of the beam (beam line 212-1), the middle of the beam (beam line212-2), and the bottom of the beam (beam line 212-3). Scan 216 (see beamlines 216-1, 216-2 and 216-3) represents the start angle, scan 220 (seebeam lines 220-1, 220-2 and 220-3) the middle angle, and scan 224 (seebeam lines 224-1, 224-2 and 224-3) the end angle of the dynamic range.The OCR of scanner system 200 is indicated by arrow 232. Also shown inFIG. 2 is a reflector 240 comprising a first prism 242 and a secondprism 244 which are fixed with respect to one another and which rotateor pivot about or with respect to the MCR, which is indicated as 246.Reflector 240 may be adjusted or pivoted about MCR 246 to differentangles (e.g., represented by positions 240-1, 240-2 and 240-3). Beamlines 216-1, 216-2 and 216-3 represent the respective reflections of top212-1, middle 212-2 and bottom 212-3 of beam 212 when reflector 240 isat position 240-3. Similarly beam lines 220-1, 220-2 and 220-3 representthe respective reflections of top 212-1, middle 212-2 and bottom 212-3of beam 212 when reflector 240 is at position 240-2, while beam lines224-1, 224-2 and 224-3 represent the respective reflections of top212-1, middle 212-2 and bottom 212-3 of beam 212 when reflector 240 isat position 240-1.

As further shown in FIG. 2, OCR 232 represents, at the intersection ofmidpoint 210 and beam lines 216-2, 220-2 and 224-2, both the center ofthe output readout beam rotation, as well as the center of the hologramvolume, of readout scanner 200. MCR 246 represents the single axis ofrotation required to give a stationary OCR scan when using aconventional scanner, such as that shown in FIG. 1. Scanner system 200may also circularize an elliptical laser diode beam (i.e., circularizean elliptical-shaped beam), may do orthogonal scanning to provide pitchcontrol, may lend itself to simple construction and control, etc. Only asingle actuator for rotating or pivoting reflector 240 is requiredbecause the degrees of freedom conventionally governed by a secondactuator and control rule are constrained optically. In particular, eachof mirrors 140 and 148 of the conventional scanner 100 shown in FIG. 1has been replaced with a reflective prism (e.g., prisms 242 and 244which comprise reflector 240) that may be, for example, silvered on itsintermediate or backside. Incoming light refracts, reflects, and thenrefracts again for each of prisms 242 and 244 of reflector 240. Becauseprisms 242 and 244 are fixed with respect to one another in reflector240 which rotates or pivots about MCR 246, extra degrees of freedom areprovided that allow for a stationary OCR 232, as well as control of thelocation of MCR 246, e.g., reflector 240 may be shifted, at or withrespect to MCR 246, vertically and horizontally while keeping OCR 232fixed and stationary.

It may also be advantageous for orthogonal scanning to locate MCR 246in-line with the incoming readout beam, as represented by the pitch axis(“PA”), indicated by 248 in FIG. 2, with orthogonal scanning beingcarried out by rotation or pivoting of reflector 240 about PA 248, asindicated by circular arrow 252 to provide pitch control. Thisorthogonal scan about PA 248 is primarily used to provide pitch controlto compensate for any small errors in the tilt or position of thehologram or holographic storage medium 204 (i.e., where the planedefined by surface 206 of medium 204 is not substantially parallel withMCR axis 246). Accordingly, the rotation or pivoting of reflectorcomponent 240 about or with respect to PA 248 to carry out suchorthogonal scans may be relatively small in magnitude, and may requirerotation or pivoting of reflector component 240 about or with respect toPA 248 of, for example, only about 0.5° in either direction and relativeto the plane defined by surface 206, as indicated by circular arrow 252.Orthogonal scanning, as illustrated in FIG. 2, may be carried outseparately from stationary OCR scanning (i.e., with respect to MCR axis246), or may be carried out concurrently with stationary OCR scanning.In order to keep the OCR relatively stationary in the orthogonaldirection it may be necessary in some embodiments to make sure the PAaxis (e.g., PA 248 in FIG. 2) is near or close to OCR and the incomingreadout beam.

In addition, the elliptical-shaped beam from a laser diode may also becircularized by refraction through the use of two reflective anamorphic(e.g., Littrow) prisms in the reflector component, as illustrated inFIGS. 4 and 5 below. A 2× circularization of the beam (i.e., the shorterdimension of the elliptical-shaped beam from the laser diode isincreased or stretched twice its original length, thus reaching orapproaching a circular shape) may be achieved with this system althoughthe prisms may also be modified for other aspect ratios. Suchcircularization may also be accomplished with a single anamorphic prism,as is illustrated in FIGS. 7 and 8 and 11 through 13, as describedbelow.

FIG. 3 schematically illustrates scanner system, indicated generally as300, using a single scan mirror 340 that may both rotate/pivot andtranslate to enable stationary OCR scanning. An idealized scanner system300 is shown in FIG. 3 with a holographic storage medium 304 which hasan upper surface 306, a reflective backing 308 to facilitateminiaturization, and a midpoint 3 10. The incoming readout input beam312 is represented by three positions corresponding to the top of thebeam (beam line 312-1), the middle of the beam (beam line 312-2), andthe bottom of the beam (beam line 312-3). Scan 316 (see beam lines316-1, 316-2 and 316-3) represents the start angle, scan 320 (see beamlines 320-1, 320-2 and 320-3) the middle angle and scan 324 (see beamlines 324-1, 324-2 and 324-3) the end angle of the dynamic range. Theoptical center of rotation (“OCR”) is indicated by arrow 332. As alsoshown in FIG. 3, mirror 340 may be adjusted or translated, for example,to three different angles (e.g., represented by positions 340-1, 340-2and 340-3). Beam lines 316-1, 316-2 and 316-3 represent the respectivereflections of top 312-1, middle 312-2 and bottom 312-3 of beam 312 whenmirror 340 is at positions 340-3. Similarly beam lines 320-1, 320-2 and320-3 represent the respective reflections of top 312-1, middle 312-2and bottom 312-3 of beam 312 when mirror 340 is at position 340-2, whilebeam lines 324-1, 324-2 and 324-3 represent the respective reflectionsof top 312-1, middle 312-2 and bottom 312-3 of beam 312 when mirror 340is at positions 340-1. As further shown in FIG. 3, the OCR 332represents, at the intersection of midpoint 310 and beam lines 316-2,320-2 and 324-2, both the center of the readout beam rotation, as wellas the center of the hologram volume, of scanner 300.

An embodiment of a scanner device that meets one or more of thesecriteria is shown in FIGS. 4 and 5, and referred to generally as 400.Scanner 400 may comprise, for example, a generally U-shaped base member,indicated generally as 404, a suspension assembly, for example, a gimbalor Cardan suspension assembly, indicated generally as 408, a reflectorcomponent, indicated generally as 412, for reflecting (and which mayalso circularize) an input scanning beam from a laser, such as laserdiode (not shown), to provide an output scanning beam and which issupported by suspension assembly 408 for rotation or pivoting, a springassembly, indicated generally as 416, a magnet component, indicatedgenerally as 420, and an actuator assembly, indicated generally as 424.Suspension assembly 408 may comprise an annular bearing, indicated as432, a mount, indicated as 436, and an axle, indicated as 440, whichalso corresponds to the MCR axis and with respect to which one end ofreflector component 412 rotates or pivots. Spring assembly 416 maycomprise a pair of spaced apart torsion springs, indicated,respectively, as 444 and 448. Reflector component 412 may comprise afirst reflective prism, indicated as 452, and a second reflective prism,indicated as 456. Actuator assembly 424 may comprise a pair of voicecoils, indicated, respectively, as 460 and 464.

Referring to FIG. 5, base member 404 may comprise a base segment,indicated as 504, and a pair of laterally spaced apart arms, indicatedas 506 and 508, extending transversely from each end of base segment 504towards the open end of base member 404, indicated as 510. Each arm 506and 508 may have an inwardly extending shoulder or pocket, indicatedrespectively as 512 and 514, which receive and hold one end (not shown),respectively, of torsion springs 444 and 448. Bearing 432 may includesan axle mounting hole, indicated as 516, which is received by agenerally cylindrical axle 518 of mount 436, and which also correspondsto the PA axis (i.e., is perpendicular to the MCR axis) about whichreflector component 412 may rotate or pivot for orthogonal scanning toprovide pitch control, and a generally cylindrical recess 520 forreceiving axle 440. Axle 440 comprises a slot 522 and 524 at each endthereof, each of slots 522 and 524 receiving and holding the other end(not shown) of respective torsion spring 444 and 448. Magnet component420 may comprise an upper prism-engaging segment 526 which engages prism456, a pair of generally fang-shaped segments 528 and 530 extending fromeach end of upper segment 526 and curving downwardly therefrom.

Torsion springs 444 and 448 provide an opposing force or biasing to thatimparted by the rotation or pivoting of suspension assembly 408 aboutboth the MCR and PA axes defined by, respectively, axle 440 and axle518, due to the movement of magnet 420 in response to the actuation ofvoice coils 460 and 460. This opposing or biasing force (preloading ofmotion) enables suspension assembly 408 to provide controlled rotationor pivoting of reflector component 412 about the MCR and PA axes. Prisms452 and 456 are fixed with respect to one another as a combined rigidreflector component 412 by being connected to (e.g. glued to) axle 440and prism-engaging segment 526 of magnet component 420. Surrounding thefang-shaped segments 528 and 530 are voice coils 460 and 464 whichcomprise actuator assembly 424.

As shown in FIGS. 4 and 5, voice coils 460 and 464, torsion springs 444and 448, and bearing 432 are fixed attached, connected, etc., to basemember 404. Magnet component 420 and voice coils 460 and 464 togetherform, in essence, a galvo or voice coil drive or actuator when energizedby passing current through voice coils 460 and 464. For example, whenvoice coils 460 and 464 are actuated with in phase sinusoids, there isonly rotation or pivoting about the MCR axis defined by axle 440 e.g.,to carry out a stationary OCR scan. When voice coils 460 and 464 are,instead, actuated with sinusoids that are 180 degrees out of phase,there is only rotation or pivoting about the PA axis defined by axle518, e.g., to carry out an orthogonal scan for pitch control. Diagonalscans (which include rotation or pivoting about the MCR and PA axis) mayalso be carried out when phase differences of the sinusoids in voicecoils 460 and 464 are between 0 and 180 degrees. Such a phase-based scandirection may facilitate simple system control electronics for scanner400.

Another embodiment of an integrated single-axis scanner device that usesa single prism (e.g., a single mirrored prism) is shown in FIGS. 6through 8, and is referred to generally as 600. Scanner 600 includes alaser, for example, in the form of laser diode 604 which is positionedon laser diode mount 608. Scanner 600 further includes a first mirror612 for relaying a light beam generated by laser diode 604, acollimation lens assembly, generally indicated as 616, for collimatingthe light beam relayed by mirror 612, and a second mirror 620 forrelaying the collimated light beam from collimation lens assembly 616.

The collimated input scanning beam from mirror 620, which is indicatedgenerally as 624, has an elliptical (i.e., non-circular) cross-sectionalprofile or shape. Input beam 624 is passed or transmitted through areflector component in the form of anamorphic reflective prism 628 whichis mounted from or carried by a prism carrier and magnet suspensionassembly, indicated generally as 630, of scanner 600. Suspensionassembly 630 is supported by or connected at one end to a flexureassembly, indicted generally as 632. (Flexure assembly 632, togetherwith suspension assembly 630, of scanner 600 generally correspond to thecombination of suspension assembly 408 and spring assembly 416 ofscanner 400 of FIGS. 4 through 5 in providing constrained rotation orpivoting with respect to the orthogonal MCR and PA axes, as well aspreloading of motion of the suspension assembly with respect to each ofthese axes.) Input beam 624 passes through prism 628, is refracted, thenreflected, then refracted again (as further described below) to providea collimated and circularized output scanning beam, indicated generallyas 636. Output beam 636 reaches holographic storage medium 640, isrefracted by upper surface 642, and is then reflected by reflectivebacking surface 644 of medium 640 towards midpoint 646 of medium 640.

As shown in FIG. 6, scanner 600 further comprises a generallyrectangular-shaped area sensor (e.g., camera), indicated generally as650, which is mounted at the forward end of scanner and over medium 640.Sensor 650 captures images of holograms recorded by medium 640 andconverts the captured images to digital data for processing by systemelectronics (not shown). Suspension assembly 630 comprises rearward,magnetic flux transmitting section, indicated generally as 654, whichincludes a base segment 658, and a pair of generally fang-shapedsegments, indicated as 660 and 662, with fang-shaped segment 660 curvingdownwardly from one end of base segment 628, and with fang-shapedsegment 662 curving downwardly from the other end of base segment 628. Amagnet 666 is mounted on or as part of assembly 630 and positionedbetween adjacent to base segment 658, and a forward magnetic fluxtransmitting section, indicated generally as 668. Rearward and forwardmagnetic flux transmitting sections 654 and 668 adjacent magnet 666 maycomprise materials that only transmit the magnetic flux generated bymagnet 666, or may comprise magnet or magnetized materials like thosewhich comprise magnet 666. Scanner 600 further includes an actuator formagnet 666 in the form of, for example, a voice coil assembly indicatedgenerally as 670, for causing assembly 630 (and thus prism 628) torotate or pivot upwardly (or downwardly) about one or more of twoorthogonal axes, as further described below.

Referring to FIG. 7, prism 628 includes a first refracting input face704 which receives and refracts input beam 624, a second upperintermediate reflecting face 708 (e.g. by silvering the backsidethereof), and a third refracting output face 712 which refracts andtransmits output beam 636 towards upper surface 642 of medium 640. Asfurther shown in FIG. 7, sensor 650 may comprise a lower CMOS sensorcover glass 716, an intermediate area sensor silicon chip 718 whichincludes a sensor active area and an upper CMOS sensor component 720.Sensor component 720 may have on the upper surface thereof a ball gridarray 722 for electrical connections to system electronics (not shown).FIG. 7 also shows the optical center of rotation (OCR) of scanner 600,which is indicated as 732, and which also corresponds to the center ofthe scan rotation and the center of the hologram volume of medium 640.FIG. 7 further shows the mechanical center of rotation (MCR) axis,indicated as 746, as well as corner or end 754 of prism 628 closest toMCR axis 746 and about which prism 628 rotates or pivots with respect toMCR axis 746.

Referring to FIG. 8, assembly 670 comprises a voice coil 804 having agenerally square-shaped bore, core, or center hole of coil 808 forreceiving fang-shaped segment 660. Assembly 670 also comprises a voicecoil 812 having a generally square-shaped bore, core, or center hole ofcoil 816 for receiving fang-shaped segment 662. Like voice coils 460 and464 of scanner 400, voice coils 804 and 812 of scanner 600 may beenergized to cause rotation or pivoting of suspension assembly 630, andthus prism 628, about one or more of two axes which are orthogonal toeach other. For example, when voice coils 804 and 812 are actuated within phase sinusoids, there is only rotation or pivoting of suspensionassembly 630 and thus prism 628 about end 754 and with respect to MCRaxis 746. When voice coils 804 and 812 are, instead, actuated withsinusoids that are 180 degrees out of phase, there is only rotation orpivoting of suspension assembly 630 and thus prism 628 about a pitchaxis (as described below) which is orthogonal to MCR axis 746. Again,diagonal scans (which include rotation or pivoting about MCR axis 746and the pitch axis) may also be carried out with when phase differencesof the sinusoids in voice coils 804 and 812 are between 0 and 180degrees.

FIGS. 9 through 10 illustrate, in greater detail, forward section 668 ofsuspension assembly 630, as well as flexure assembly 632 which isattached or mounted thereto. Forward section 668 includes a generallyC-shaped forward flexure assembly mounting portion 904, and a rearwardportion 908. Rearward portion 908 comprises a base segment 912 and apair of kinked or bent arms, indicated as 916 and 918, extendingrearwardly and downwardly from each end of base segment 912. Arm 916comprises a shorter segment 920 extending generally downwardly from oneend of base segment 912, and a longer segment 922 extending generallyrearwardly from shorter segment 918. Similarly, arm 918 comprises ashorter segment 924 extending generally downwardly from the other end ofbase segment 912, and a longer segment 926 extending rearwardly fromshorter segment 924.

Flexure assembly 632 comprises a pair of spaced apart upper flexurecomponents 930 and 932 mounted underneath and to flexure mountingportion 904 of forward section 668, and a pair of lower flexurecomponents 934 and 936 mounted underneath and to, respectively, upperflexure components 930 and 932. Upper flexure component 930 comprises agenerally L-shaped lower base segment 940, and a generally rectangularshaped upper segment 942. Lower base segment 940 has a longer forwardlyextending section 944 and a shorter section 946 extending inwardly fromone end of section 944. At least one flexure segment, for example, inthe form of outer flexure segment 948 which extends diagonally upwardlyand rearwardly in one direction to connect longer section 944 of lowerbase segment 940 to upper segment 942, while another inner flexuresegment 950 extends diagonally and forwardly in the opposite directionto connect shorter section 946 of lower base segment 940 to uppersegment 942, with outer and inner flexure segments 948 and 950 togetherforming a generally X-shaped structure. Similarly, upper flexurecomponent 930 comprises an L-shaped lower base segment 952, and arectangular shaped upper segment 954. Lower base segment has a longerforwardly extending section 956 and a shorter section 958 extendinginwardly from one end of section 956 and towards opposite shortersection 946. At least one flexure segment, for example, in the form ofouter flexure segment 960 which extends diagonally upwardly andrearwardly in one direction to connect longer section 956 of lower basesegment 952, while another inner flexure segment 964 extends diagonallyupwardly and forwardly in the opposite direction to connect shortersection 958 of lower base segment 956 to upper segment 954, with outerand inner flexure segments 960 and 964 together forming a generallyX-shaped structure. Upper flexure components 930 and 932 of flexureassembly 632 (due to the flexibility provided or imparted by therespective X-shaped structures of upper flexure segments 948/950 andupper flexure segments 960/964) provides suspension assembly 630 (whichis connected to flexure assembly 632) with the ability to rotate orpivot with respect to a stationary MCR axis 746, thereby also enablingor permitting prism 628 to rotate or pivot at a fixed position about end754, and thus provide the ability to carry out stationary OCR scanningwith scanner 600. In addition, the respective combination of flexuresegments 948/950 and 960/964 of upper flexure components 930 and 932provide the means for preloading the motion of suspension assembly 630to thus enable prism 628 to controllably rotate or pivot with respect toMCR axis 746.

Lower flexure component 934 comprises an upper L-shaped segment 972, arectangular-shaped lower base segment 974, and at least one flexuresegment, for example, flexure segment 976, which extends diagonallyupwardly and outwardly (i.e., perpendicular to the directions that upperflexure segments 948/950 diagonally extend) to connect lower basesegment 974 to upper segment 972. Similarly, lower flexure component 936comprises an upper L-shaped segment 982, a rectangular-shaped lower basesegment 984, and at least one flexure segment, for example, flexuresegment 986 which extends diagonally upwardly and outwardly (i.e.,perpendicular to the directions that upper flexure segments 960/964diagonally extend) to connect lower base segment 984 to upper segment982. Lower flexure components 934 and 936 of flexure assembly 632, dueto the flexibility provided or imparted by respective lower flexuresegments 976 and 986 which extend diagonally upwardly and outwardly fromrespective lower base segments 974 and 984, provides assembly 630 withthe ability to rotate or pivot about PA 992 (which is orthogonal orperpendicular to the MCR axis 746), as indicated by circular arrow 994,to thereby also enable or permit prism 628 to rotate or pivot withrespect to PA 992, and thus provide for the ability to carry outorthogonal scanning with scanner 600. In addition, respective flexuresegments 976 and 986 of lower flexure components 930 and 932 provide themeans for preloading the motion of suspension assembly 630 to thusenable prism 628 to controllably rotate or pivot with respect to PA 992.

The benefits of scanner 600 shown in FIGS. 6 through 10 include: (1) theability to use a single prism element 628 with refractive input face704, reflective intermediate face 708, and refractive output face 712 asthe reflector component; (2) prism 628 may be rotated or pivoted withrespect to a stationary MCR axis 746, thus providing stationary OCRscanning about a well defined OCR 732; (3) prism 628 may provide a large(e.g., at least up to about 20 degree) scanning range which may beideally suited to holographic data storage; (4) prism 628 may also actas an anamorphic or circularizing prism in that elliptical-shaped inputbeam 624 exits prism 628 as a substantially circular-shaped output beam636; and (5) when prism 628 is rotated or pivoted about PA 992 (see FIG.9), transverse or orthogonal scanning may also be possible for thepurpose of, for example, pitch control.

The performance characteristics of the scanner 600 and especially prism628 in operation are further illustrated in FIGS. 11 through 13. FIG. 11provides a scanning diagram, indicated generally as 1100, whichillustrates schematically the passage of input beam 624 through prism628 when positioned at one angle. As shown in FIG. 11, input beam 624reflected or directed from mirror 620 comprises a plurality ofcollimated beam lines, of which five representative beam lines 624-1through 624-5 are shown. Input beam 624 (see beam lines 624-1 through624-5) is refracted by input face 704 of prism 628 to provide arefracted beam 1104, of which five corresponding refracted beam lines1104-1 through 1104-5 are shown. Refracted beam 1104 (see beam lines1104-1 through 1104-5) is then reflected by reflective face 708 of prism628 to provide reflected beam 1108, of which five correspondingreflected beam lines 1108-1 through 1108-5 are shown. Reflected beam1108 (see beam lines 1108-1 through 1108-5) is then refracted by outputface 712 to provide output beam 636, of which five corresponding outputbeam lines 636-1 through 636-5 are shown. Output beam 636 (see beamlines 636-1 through 636-5) reaches and is then refracted by uppersurface 642 of medium 640 to provide corresponding refracted beam lines642-1 through 642-5. Refracted beam lines 642-1 through 642-5 reach andare then reflected by backing surface 644 to provide five correspondingreflected beam lines 644-1 through 644-5. Reflected beam lines 644-1through 644-5 are shown as terminating at midpoint 646 of medium 640.

FIG. 12 provides a scanning diagram, indicated generally as 1200, whichillustrates schematically the passage of input beam 624 through prism628 when rotated or pivoted to three different positions or anglescorresponding to a 35° output beam, indicated generally as 1204, a 45°output beam, indicated generally as 1208, and a 55° output beam,indicated generally as 1212, about end 754 and with respect to themechanical center of rotation (MCR) axis, indicated as 1246. (Positionor angle 1212 corresponds to the position or angle of prism 628 shown inFIG. 11.) Beam lines indicated as 1204-1 through 1204-3 correspondgenerally to the top, middle and bottom of input beam 624 as it passesthrough prism 628 when rotated to position 1208 (35° output beam). Beamlines indicated as 1208-1 through 1208-3 correspond generally to thetop, middle and bottom of input beam 624 as it passes through prism 628when rotated to position 1208 (45° output beam). Beam lines indicated as1212-1 through 1212-3 correspond generally to the top, middle and bottomof input beam 624 as it passes through prism 628 when rotated toposition 1212 (55° output beam). As shown in FIG. 12, middle beam lines1204-2, 1208-2 and 1212 reach the optical center of rotation (OCR),indicated as 1232, which also corresponds to the center of the scanrotation and the center of the hologram volume.

In determining the beam angle of output beam 632 when prism 628 isrotated or pivoted to the various positions or angles (e.g., positionsor angles 1204, 1208 and 1212), reference is made to an output beamangle reference line, indicated by dashed line 1250, which is orthogonal(normal) to surface 642 of medium 640. For example, the beam angle madeby output beam lines 1204-1, 1204-2 and 1204-3 with respect to surface642 and relative to reference line 1250 is 35°, thus providing a 35°output beam 636. Similarly, the beam angle made by output beam lines1208-1, 1208-2 and 1208-3 with respect to surface 642 and relative toreference line 1250 is 45° (thus providing a 45° output beam 636), whilethe beam angle made by output beam lines 1212-1, 1212-2 and 1212-3 withrespect to surface 642 and relative to reference line 1250 is 55° (thusproviding a 55° output beam 636). In other words, scanner 600illustrated in FIG. 12 provides at least a 20 degree scan range (or thedifference between the angle of output beam 636 when prism is rotated orpivoted to position 1204 and the angle of output beam 636 when prism isrotated or pivoted to position 1212). It should also be understood thatthe positions 1204, 1208 and 1212 of prism 628, the angles for outputbeam 636, and the scan range shown in FIG. 12 are illustrative, and thatprism 628 may be rotated or pivoted to positions other than those shownin FIG. 12, may provide angles for output beam 636 other than thoseshown in FIG. 12, and may have wider (or narrower) scan ranges than thatshown in FIG. 12.

FIG. 13 provides a circularization diagram, indicated generally as 1300,which illustrates schematically the circularization that may occurduring the scans shown, for example, in scanning diagram 1200 of FIG.12. The elliptical cross-sectional shape of input beam 624, prior tobeing processed by prism 628, is shown in circle 1304. Elliptical shapedinput beam 624 may then be processed by prism 628, as indicated by “IN”arrow 1310 in FIG. 13. After processing by prism 628 (see scanningdiagram 1200), the processed output beam 636 leaves prism 628, asindicated by “OUT” arrow 1330 in FIG. 13. The resulting circularcross-sectional shape of output beam 636, after processing by prism 628,is shown in circle 1334. As further shown, in FIG. 13, the ellipticalcross-section of input beam 624 in circle 1304 has a short dimensionaxis, indicated by dashed line 1350, and a long dimension axis,indicated by dashed line 1354, which is orthogonal or perpendicular toshort dimension axis 1350. In order to circularize input beam 624, prism628 increases or “stretches” beam 624 when processed (i.e., “IN” arrow1310) along short dimension axis 1350, with the degree of “stretching”or circularization being referred to in terms of Nx, where N is how muchbeam is stretched along axis 1350. For example, the 20 degree scanillustrated in FIG. 12 may provide the following degrees ofcircularization of input beam 624: for a 35° output beam 628, the degreeof circularization may be as much as 1.9× (i.e., N=1.9); for a 45°output beam 628, the degree of circularization may be as much as 2.0×(i.e., N=2.0); and for a 55° output beam 628, the degree ofcircularization may be as much as 2.25× (i.e., N=2.25). The particulardegree of circularization that may be achieved may depend on thespecific design of the scanner. Laser diodes often requirecircularization of from about 1.7× to about 2.3× which may be achievedby embodiments of scanners of the present invention, e.g. scanner 600,thus avoiding the need for additional circularizing components whenusing a laser diode.

It should be appreciated that the specific embodiments illustrated inFIGS. 1 through 13 are provided to illustrate the teachings of thepresent invention. Alterations or modification within the skill of theart of the specific embodiments illustrated in FIGS. 1 through 13 areconsidered within the scope of the present invention, so long as thesealterations or modifications operate in a same or similar manner,function, etc. These modifications may include the use of a singleassembly, member, element, component, etc. (in place of a plurality ofassemblies, members, elements, components, etc.), the use of a pluralityof assemblies, members, elements, components, etc. (in place of a singleof assembly, member, element, component, etc.), the changing of theorder, orientation, direction, position, etc., of any of the assemblies,members, elements, components, etc., the combining or integrating of anyof the assemblies, members, elements, components, etc., into a single orunified assembly, member element, component, etc., or the ungrouping ofan assembly, member, element, component, etc., into a plurality ofassociated assemblies, members, elements, components, etc. For example,while the specific embodiments illustrated in FIGS. 4 through 13 showscanners 400 and 600 being oriented generally horizontally, scanners 400and 600 may also be oriented generally vertically, or in any otherorientation without departing from the scope of the present invention.

All documents, patents, journal articles and other materials cited inthe present application are hereby incorporated by reference.

Although the present invention has been fully described in conjunctionwith several embodiments thereof with reference to the accompanyingdrawings, it is to be understood that various changes and modificationsmay be apparent to those skilled in the art. Such changes andmodifications are to be understood as included within the scope of thepresent invention as defined by the appended claims, unless they departtherefrom.

1. A device comprising a scanner having a mechanical center of rotationand an optical center of rotation, the scanner comprising: a reflectorcomponent for reflecting an input scanning beam to provide an outputscanning beam; means for supporting the reflector component for pivotingof the reflector component about one end of the reflector component withrespect to the mechanical center of rotation so that the output scanningbeam provides a scan which is stationary with respect to the opticalcenter of rotation; means for enabling the support means to providecontrolled pivoting of the reflector component about the one end; amagnet component which when actuated causes pivoting of the reflectorcomponent about the one end; and means for actuating the magnetcomponent to thereby cause pivoting of the reflector component about theone end.
 2. The device of claim 1, wherein the support means comprises agimbal suspension assembly.
 3. The device of claim 2, wherein thescanner has a pitch axis orthogonal to the mechanical center of rotationfor orthogonal scanning, and wherein the gimbal suspension assemblycomprises: a mount having a generally cylindrical axle corresponding tothe orthogonal rotational axis, and a generally cylindrical recess; abearing mounted on the base member which is received by the cylindricalaxis; and a second axle corresponding to the mechanical center ofrotation which is received by the cylindrical recess and which has endsmounted on the base member.
 4. The device of claim 3, wherein thereflector component comprises a first prism and a second prism.
 5. Thedevice of claim 4, wherein each of the first and second prisms comprisea reflective prism.
 6. The device of claim 5, where each of the firstand second prisms comprise an anamorphic reflective prism.
 7. The deviceof claim 4, wherein the actuating means comprises one or more voicecoils.
 8. The device of claim 7, wherein the magnet component comprisesan upper prism-engagement segment which engages one of the first andsecond prisms, and pair of generally fang-shaped segments, onefang-shaped segment extending from each end of the upper segment andcurving downwardly therefrom, and wherein the actuating means comprisesa pair of voice coils, one voice receiving one of the fang-shapedsegments, the other voice coil receiving the other fang-shaped segment.9. The device of claim 8, wherein when the voice coils are actuated within phase sinusoids, the reflector component pivots about the mechanicalcenter of rotation so as to carry out a stationary OCR scan, and whereinwhen the voice coils are actuated with sinusoids 180 degrees out ofphase, the reflector component pivots about the pitch axis so as tocarry out an orthogonal scan.
 10. The device of claim 9, wherein thevoice coils are actuated to carry out a stationary OCR scan and anorthogonal scan.
 11. The device of claim 1, wherein the scanner has ascan range of up to about 20°.
 12. The device of claim 11, wherein thescanner provides an output scanning beam having a beam angle in therange of from about 35° to about 45°.
 13. The device of claim 1, whereinthe enabling means comprises a spring assembly to preload motion of thesupport means.
 14. The device of claim 13, wherein the spring assemblycomprises a pair of spaced apart torsion springs.
 15. The device ofclaim 1, wherein the support means has a flexure assembly mountingportion and wherein the enabling means comprises a flexure assemblyhaving a pair of spaced apart upper flexure components mountedunderneath and to the flexure means mounting portion, each upper flexurecomponent having at least one flexure segment for enabling thereflective prism to controllably pivot with respect to the mechanicalcenter of rotation.
 16. The device of claim 15, wherein the scanner hasa pitch axis orthogonal to the mechanical center of rotation fororthogonal scanning, and wherein the flexure assembly further comprisesa pair of spaced apart lower flexure components, each lower flexurecomponent being mounted underneath one of the upper flexure components,each lower flexure component having at least one flexure segment forenabling the reflective prism to controllably pivot with respect to thepitch axis.
 17. The device of claim 1, wherein the mechanical center ofrotation is stationary.